DD IEC/PAS 62344:2007

INTRODUCTION
1 Scope
2 Basic concepts
   2.1 Monopolar system
   2.2 Bipolar system
   2.3 Mixed or combined systems
3 Electric field as the decisive factor for selection
   of site
   3.1 Why is the electric field the decisive factor?
   3.2 Data necessary to determine the field
        3.2.1 Reference currents (or electrode rating)
        3.2.2 Resistivity data
   3.3 Considerations on site selection
   3.4 Calculation of field
   3.5 Apparent resistivity
4 Impact of the field on buried metallic objects
   4.1 Impact on non-insulated buried metallic objects
   4.2 Impact on insulated metallic objects
   4.3 Impact on an a.c. grid
   4.4 Reduction of impact due to polarization
        4.4.1 Polarization on non-insulated metallic objects
        4.4.2 Polarization on insulated metallic objects
        4.4.3 Reduction of star-point currents due to
               polarization
5 Compass errors
6 Types of electrode stations
7 Design aspects for land electrodes
   7.1 General
   7.2 Heating of soil
   7.3 Moisture content of soil/electric osmosis
   7.4 Material for land electrodes
        7.4.1 Inner conductor
        7.4.2 Coke or graphite powder filling
   7.5 Geometric layout of the electrode
        7.5.1 Horizontal arrangements
        7.5.2 Vertical arrangements
   7.6 Step voltage
   7.7 Touch voltage
8 Design aspects for sea electrodes
   8.1 General
   8.2 Sea electrodes using titanium as active part
        (anodic operation)
        8.2.1 Material
        8.2.2 Current density and gradients
        8.2.3 Geometric layout
   8.3 Sea electrodes using coke or SiFeCr-rods as
        active parts (reversible operation)
        8.3.1 Overheating risk
        8.3.2 Material for sea electrodes
        8.3.3 Geometric layout of reversible sea electrodes
   8.4 Sea electrodes using bare copper conductors as
        active parts (cathodic operation only)
9 Design aspects for shore electrodes
   9.1 General
   9.2 Beach electrode stations
   9.3 Pond electrode stations
10 Chemical aspects
11 Connection converter station - Electrode station
   11.1 Separation of a.c. grid from electrode station
   11.2 Constructional principles of electrode connection
   11.3 Detection of faults on electrode connections
   11.4 Electrode connection terminations
12 Operating experience - Reliability, availability,
   maintainability
13 Commissioning
14 List of references
Appendix 1
Appendix 2
Appendix 3
Appendix 4 - Heating of soil - Numerical example
Appendix 5

Provides a guideline for the design of electrode stations for HVDC links intended for ground return.

Provides a guide for the design of electrode stations for HVDC links intended for ground return. This design guide was prepared by the CIGRÉ Working Group 14.21: HVDC Ground Electrode Design during the period 1995-1998.